MADISON – The record-breaking temperatures, strong thunderstorms, and wind gusts that swept through Wisconsin last week could be linked to a warmer climate.
The storms were likely driven by warming sea temperatures and altered airflows within the atmosphere. They left thousands of Wisconsinites without power Thursday morning, as wind gusts continued their destructive assault on the state.
Warm temperatures Wednesday shattered records for Dec. 15 in both Madison and Milwaukee. In Madison, the temperature reached 68 degrees, according to the National Weather Service, far higher than the old record of 52 degrees set in 2011.
And in Milwaukee, the temperature reached 67 degrees on Wednesday, climbing far above the record of 55 degrees for the same day back in 1891.
The record for the warmest ever December day in Wisconsin was also broken in Boscobel, where the temperature reached 72 degrees during the day.
The warm temperatures were followed by strong winds by an overnight storm system that swept across the state. In some places, gusts of wind reached 60 to 70 miles per hour, causing power outages, downed trees and property damage.
Jonathan Martin, professor of atmospheric and marine sciences at the University of Wisconsin Madison said that stormy weather is not uncommon for this time of year.
He said, “Even in an average year, under perfectly ordinary circumstances, we’d see a nice progression from pretty stormy days to clear days followed by a few stormy days.” “But there’s a couple of things which might be fueling a little more punch for these things.”
Martin said that one of these things is a strong personality. La NiñaThe hemisphere’s air circulation is altered by the. These changes allowed for the storm system’s passage over the West Coast, desert southwest, and eventually Wisconsin. It brought with them extraordinary winds, extremely warm, and moist air.
And while the winds and temperatures were certainly outside the normal for Wisconsin, the dew point was also shockingly high — 58 in Madison.
Martin said that it felt like a springday. “It was just amazing to have a day like that on December 15th.
Martin stated that the extreme heat, as shown by the broken records in Milwaukee, Madison and other cities, was not expected for this time of year. The month’s early days may see highs in the 50s, 60s, but the mid-month will see the Midwest enter winter.
He said, “We have really strange and unusual circumstances here.” “And in background, of course there is a global heat increase that is undeniable. It probably had some impact in pushing us over the record level.”
Martin said that precise data on the relationship between this particular storm and climate change will be required. This study will likely be underway in coming days. However, there are obvious influences of climate change that could be linked to this system.
One of these influences is the Gulf of Mexico’s higher temperatures. This makes it easier to evaporate water into the atmosphere, increasing precipitation and humidity. Martin stated that it can be difficult to find connections without research.
Martin stated, “There is unambiguous evidence that the globe is warming up.” “It is unequivocally a function of human industry having changed the chemical composition of the atmosphere in such a way to encourage the warming.”
Martin’s words were echoed by the Intergovernmental Panel on Climate Change which is the United Nations body responsible for assessing science related to climate change.
This year, the group issued the most severe climate change warning in the world. It stated that it was unambiguous that human actions such as the release greenhouse gases are driving climate change. This is causing more extreme weather and higher temperatures than ever before.
Martin said he and other researchers are working to determine the links between storm events like this one and others that Wisconsin has seen in recent years, and that the state will likely see in the next five to 100 years.
He stated, “My guess would be that (global heating) had a 10-20% effect on the intensity of this particular event.”
The frequency of tornado-producing storms could increase
The storms brought with them tornadoes which are extremely rare for December in Wisconsin.
Surveyors from the National Weather Service office at La Crosse confirmed that there was an EF-2 tornado in Clark County north of Neillsville.
Neillsville, roughly 50 miles southeast of Eau Claire, was one of four places so far where La Crosse-based surveyors confirmed a tornado was produced by the storms. An EF-1 tornado struck Rudd, Iowa. A tornado of magnitude 0 was also confirmed near Lewiston in Minnesota. Another tornado was confirmed in Stanley, but the National Weather Service in the Twin Cities did not yet know how strong the tornado was.
They were Wisconsin’s first December tornadoes since 1970, according to the National Weather Service. Four tornadoes were reported in central Wisconsin on December 1, while another was recorded in Dodge County on December 3.
While research is still ongoing on the links between climate and change, severe storms which create tornado conditions are increasing as the world heats.
Steve Vavrus, a senior scientist from the Nelson Institute for Climatic Research UW-Madison said that the state’s exposure to tornadoes will only grow.
“On the whole we don’t know how (tornadoes will) change in the future. We don’t know if they’ll become more intense or less intense, more frequent, more common, or less common,” he stated. “But in warmer climates, we’ll see tornadoes more common in the fall and winter, when the weather is more favorable.
December storms are not always a good indicator of a mild winter.
The unusually warm temperatures are delaying the onset winter in Wisconsin, but they don’t mean that winter will be mild.
Martin said that “the atmosphere has just about zero memory,” so an event that takes place this week has no or very little impact on one that takes place two weeks downstream. “So it is difficult to know if this winter will be affected similarly or will play out in the same manner as what we have had.”
That said, data seems to suggest that winter is getting shorter on both ends of the season — and storms on either side of the season are getting stronger.
Storms such as the one in Wisconsin or the deadly tornadoes in Kentucky that occurred outside of the normal season for tornadoes may become more common.
Martin said, “It won’t take 100 years for the next high of 68 degrees in the middle December to come along.” It could be 10 years for the next 68-degree temperature high in December, or the same for the tornadoes. We might see them more often in the future in places that we haven’t seen them since December.
Sophie Carson, a member of the Milwaukee Journal Sentinel staff, contributed to this report.
Laura Schulte can be reached at email@example.com and on Twitter at @SchulteLaura.